Method of making sound records



Oct. 28, 1941. A. c. BLANEY 2,260,699

METHOD OF MAKING SOUND RECORDS Filed Jan. 50, 1959 Aer/ g2 C. 5LANEY,

SMMM

' 1 making oi such records.

. Patented 28, t

UNITED STATES PATENT OFFICE Q Mn'rnon or m s om'mom I Arthur 0. Blaney, Lol Axgele's, cum, assignor to Radio Corporationot Delaware This invention relates to the production of motion picture sound records and particularly to the recording and printing processes involved in the The usual method for the production of motion picture sound records is to light-impress a film with light varying transversely of the sdund track portion of the film (variable area records) or varying'in intensity (variable density records) in accordance with the form of the sound waves of the signal to be recorded. Noise reduction is usually applied to variable area records by shuttering of! the light from the unusedportions of the sound track area, and, isjusuaily applied,

to variable density records by operating between one end of the density characteristic and the central point thereof.

Application January 30, 19st), Serial I 7 Claims. (or 274-46) erica; a corporation oi assigned tothe' same assignee as the present application.

In the process of producing a final motion picture, the various shots made each day are reviewed by directors, actors, sound technicians and' others. Several sound records are therefore required'ior this purpose. Also, additional records are usually required for the rerecording process wherein several tracks are combined to produce a composite sound track ior tbe'final picture. Thus, although the direct sound record -recording system produces a record which may For the purpose of description, reference here inafter to sound recor will mean a filmasound record track as finally produced for reproduction.

in theatres, while a "negative record will refer to a film sound record track from which a sound record is printed. The usual method of making sound records is to first make a negative record, with the sound recording apparatus and then make a print for reproduction. Normally, there;

fore, the sound record is a print of a negative --sound record. The present invention relates to recording systems whereby a final sound record is recorded directly with therecording apparatus and such a record will be called, for purposes of description, afdirect sound record.

Variable area recording systems for producing direct sound records are well known This type of recording has many advantages over the negative method, inasmuch as it eliminates the printing step'required'as mentioned above. Another advantage is that noise reduction appears as opaque areas alter the first development, thus eliminatingthe deleterious eflects oi dirt on the negative, while these areas may be exposed to a greater extent toprovide greater noise reduction.

Italso has the advantage of permitting simpli-r fied anticipatory noise reduction, which permits the sound track area to be prepared in anticipation or the application of the signal, thus avoiding peak-clipping prevalent in systems where the noise reduction and signal are impressed at the same point on the film. Also, where only one copy is,required, the cost of makinga print is saved. Such a direct sound. record recording system has been disclosed and claimed in copending application Serial No. 338,424, filed June 1,1940, as a continuation oi,application Serial No. 168,173, filed October 9, 1937, and

normal developing process.

be immediately used, more than this one record 'is required. Ordinarily, to produce additional records it is necessary to first print a negative subsequently printed. By these steps some of the advantages of the direct record system are lost, as there is still the opportunity for dirt to appear on the interm ate negative.

Anobject oi the present invention, therefore, is to facilitate the productiofi'of sound records.

' Another object of the invention is to make sound records directly irom sound records in the a further object of the invention is to eminnate the necessity of making a negative record from a sound record to obtain duplicate sound record prints thereof.

A further object is to make film prints from sound records without increasing the noise level of theoriginal sound record.

Although the novel features which are believed to be characteristic of this invention are pointed out with particularity inthe claims appended herewith, the manner of its organization and the mode of its'operation will be better understood by referring to theiollowing description read in conjunction with the accompanying drawing forming a part thereof, in which Figure 1 is a negative record of a duplex sound track;

Figure 2 is a sound record printed from the negative record oi Fig. 1;

shownoi' a sound track of the standard duplex type, wherein the sound modulations have a transparent area I and opaque areas 8, and noise reduction transparent areas I. The opaque areas I are bounded by traces made in accordance with the signal modulations and the envelope oi the K signal modulations. Upon this negative is shown a dirt spot it, which, we may assume, is opaque gird adherent to the transparent area I of the Now, in printing the negative of Fig. 1, the sound record of Fig. 2 is the result, the dirt spot in appearing as a transparent image iii in the opaque portion II. In this print, of course, the transparent area 5 is now Opaque area l3, and the opaque areas 6 are now transparent areas I. It is well known that the dirt spot image III, being transparent in an opaque area, will produce a plop or click according to its size, while a series of such images or holes will of course produce hissing, or one form of ground noise. 'It will also be seen that although the sound record in Fig. 2 may be usedfor reproduction of the sound track, it was necessary to go through the steps of developing the negative, printing, and developing the print to produce such a record. Each of these steps not only increases the noise level, but is also accompanied by a definite loss in quality. Thus the elimination of any of these steps is a decided advantage. Several prints, of course, may be made from the negative of Fig. 1 for review room and rerecording purposes, while the result of the rerecording process produces a master negative from which the sound records for the picture are printed.

Now, in Fig. 3, there is shown a direct sound record with a track of the standard duplex type shown in Figs. 1 and 2 and which may be made with the apparatus disclosed and claimed in the above-identified copending application. This record is suitable for reproduction and is seen to have the same relative opaque and transparent areas as the record of Fig. 2. The dirt spot in also appears on this sound record, but, being opaque and occurring in the opaque portion of the sound track area, it causes no deleterious efiect or extraneous noise. Although there may be a slight variation in density between the area of the dirt spot and the remainder of the opaque portion it, it is insufilcient to create any effective light differential in the photocell. This result, of course, is attributable to the direct record system such as disclosed in the above-identified copending application.

However, as mentioned above, more than one print is required in the normal production of the motion picture for which the sound record is'required. Normally, additional records would be produced by printing a negative from the record of Fig. 3, which would appear as shown in'Fig. 1, from which other sound record prints may be made. There are added two printing steps, two developments and one film. The present invention eliminates one of these printings, one of the developments and the negative film. To accomplish this, a sound record print as shown in Fig.

4 is made directly from the direct sound record. This single printing may be carried out by two methods. One is to subject the printed stock to the well known amateur film reversing process, although this process is not preferred, since it is not adaptable or suitable to motion picture studios or commercial motion picture laboratories where the special reversing developer is notusually available. Furthermore, this special process is comparatively expensive and complicated. The preferred method of the invention, therefore, accomplishes the result by the use of a direct copy emulsion stock now being manufactured by Eastman Kodak Company and named auto-positive" and inwhich the reversing has been done before exposure and which thus only requires the usual type of normal development now in commercial studio and laboratory use. This method will produce a sound record print from a direct sound record or a negative print from a negative. Thus, no change in commercial processing is required.

All that is required for the preferred method, therefore, is to originally record as a direct sound record, subject this negative or direct sound record to the usual commercial processing (not reversal process), which results in a. record such as shown in Fig. 3, then print the direct record in a contact or optical printer to the auto-positive stock, and then subject this printed stock to the normalcommercial developing process (not re-- versal process) in use in commercial laboratories or in, studios where processing is done.

The direct sound record of Fig. 3 may, therefore, serve as a negative for printing purposes and from which as many duplicate sound records as desired maybe made. duplicates in accordance with the invention, all the advantages of direct sound record recording are retained. For instance, the dirt spot III of Fig. 3 now appears in the record of Fig. 4 as an opaque image l0 in'the opaque noise reduction area l1. Also, there is no negative film required on which dirt will produce holes in the opaque areas of the final print. Thus, the duplicat prints not only may be-made directly from the direct sound record used as a negative, but this method has the advantage over negative printing of eliminating noise caused by dirt on the direct positive which would cause noise if on a negative. Also, by the use of the direct copy emulsion for printing from a direct sound record, all the other advantages attributable to, and inherent in, the direct record method of recording are retained, such as anticipatory noise reduction, saving in time and film, etc.

Although the above invention has been disclosed as embodied in a variable area sound track of a specific type,- it is to be understood that all the advantages thereof are also attendant upon its use for other types of variable area tracks as well" as in variable density systems. It is also .to be understood that this printing process is applicable to the making of additional copies of sound record prints from sound record prints made fromnegatives such as shown in Fig. 2. ,Thus, a first print used as a negative may provide cleaner duplicates than the original negative after several prints have been made from the latter.

I claim as my invention:

1. The method of producing a sound film track record comprising light-impressing a normal negative film in accordance with sound waves to be recorded, said light impression and the normal development of said film producing a positive record of said sound waves, light-impressing a second film with the light variationsproduced by said positive film, and reversing by d ment of said second film to produce a positive duplicate of said first film.

2. The method of making sound film track records comprising recording a direct sound record from the signal being recorded, normally processing said record, said recording and said processing producing a positive sound track record, exposing a direct copy emulsion film stock in accordance with the light variations of said positive record, and normally developing said stock to produce an exact duplicate of said direct sound record.

In the making of such 3. The method of making sound film track prints comprising the step of exposing a normal negative film emulsiOn so that upon normal development thereof a positive record is produced, exposing a plurality of direct copy emulsion films to light variations produced by said positive record, and normally developing said direct copy emulsion films in the same manner as said first film.

4. The method of making a plurality of sound film track prints of a certain signal comprising modulating light with said signal and light-impressing a normal negative film emulsion so that upon normal development thereof a positive record of said signal is produced, exposing an auto-positive stock to light variations corresponding to said positive record, and subjecting said stock to the same development given said first film.

5. The method of producing a sound film track 20 record comprising light-impressing a normal negative film in'accordance with a signal, normally developing said film to produce a record of said signal, the variations in light impressed upon said film being'such as to produce a positive sound record of said signal, exposing a second film to variations in light produced by said first record, and normally developing said second film to produce a duplicate of said direct sound record.

6. The method of producing a plurality of sound film track records comprising recording a negative sound record, printing a positive sound record from said negative, exposing a plurality of films of direct copy emulsion film stock to light variations in accordance with said positive sound record, and normally developing said films to produce duplicate positive films.

7. The method of producing a sound film track record comprising the steps of light-impressing a normal negative film in accordance with sound waves to be recorded, producing from said light impression and the normal development-of said film a positive record of said sound waves, and

light-impressing a second film with the light variations produced by said positive film record and directly producing a positive duplicate of said first film.

ARTHUR C. BLANEY. 

